If the Sri Lankans agree to send their team to Pakistan, it would be the first tour by a Test playing nation since the infamous March 2009 attack incident in Lahore where militants attacked the Sri Lankan team bus.

"We have got a positive response from them to the invitation we sent them. The good thing is that they haven't outrightly rejected the invitation," a PCB official said.

"What they have said is they will discuss the issue internally and with its players and then get back to us," he said.

The official made it clear that the PCB had given no time frame to accept the invitation.

"All that can be decided at a short notice but first and foremost they have to accept the invitation first," he said.

The PCB official said the board was hopeful since the Sri Lankans had always supported Pakistan and their President himself had said he would like to see his countrymen play in Pakistan.

The PCB sent the invitation after Sri Lankan President Mahinda Rajapakse told his Pakistani counterpart Mamnoon Hussain he will send his cricket team to Pakistan on the sidelines of a summit in China earlier this month.

"The words of the Sri Lankan President are a big boost for us and we feel this is the best time to test the waters," PCB Chairman Najam Sethi had said.

The PCB official said they were aware of the challenges the board was facing because of refusal of teams to tour Pakistan because of security reasons.

Six Pakistani policemen and a van driver were killed in the attack on the Sri Lankan team bus while some visiting players were wounded.

The official confirmed that the PCB had drawn up a comprehensive security plan if the Sri Lankans agreed to tour.

"The matches would be limited to Lahore and the visiting team can also be housed at the National cricket academy," he added.

Asked about the letter sent to the England and Wales cricket board (ECB) regarding the action it intended to take against its T20 captain, Stuart Broad, for his controversial remarks on the bowling action of Saeed Ajmal, the official said the ECB had only informed them they were looking into the matter.